1. Field of the Invention
The present invention relates to a printer device, a data processing device of print data, and a printer system including these devices.
2. Description of the Related Art
In a typical printer system, a printer device is connected to a host computer and a program referred to as a printer driver for operating a printer is installed in the host computer.
A printer driver in a host computer converts print objective data to print data described in a printer-understandable format, namely, a printer-interpretable language (printer control language), and this print data is sent to a printer by an operating system. Printer control languages have been independently developed by the respective printer makers and the like and there are various types of printer control languages such as ESC/Page, Post Script and so on.
A printer device receives print data described in a printer control language, performs language analysis of the print data, and converts the print data to an intermediate code adaptable to processing within a printer (generation of an intermediate code). For example, an intermediate code can be expressed as display lists composed of printable small segments including fonts, image, operands for graphic operation such as “LINE”, “ARC” and so forth. The printer device thereafter rasterizes the intermediate code into a bit image (rasterization of an intermediate code) and conducts printing.
Here, if one page worth of bit image is to be entirely stored, a large storage area would be required and the memory efficiency will be reduced.
Therefore, conventionally, one page worth of bit image was divided with a plurality of bands, and an intermediate code as generated and rasterized into a bit image in such band units. Then, the printer device successively releases storage areas with respect to the bit image that has been printed, and controls the bit image of the following bands to be stored in the released storage areas (print control). In this structure, memory efficiency may be improved as it is sufficient to maintain storage areas only for a few bands. The storage area for such few bands is called a band buffer.